Fluctuations in power consumption on the large Danish (132/150 kV) electrical grid is a problem that increases in severity the shorter the timescale of the fluctuations.
An area where very large but brief power consumption is seen is in the electrified part of the Danish railway system, where starting trains draw a very large but brief power. This is a problem, especially in light of the planned large scale electrification of the Danish railway. At present transformer stations are severely over dimensioned in order to provide the necessary peak power.
In this project, we will design, construct, install and demonstrate an energy storage device at an electrical railway transformer station, to reduce the peak load on the overlaying electrical grid. The energy storage device will instead continuously draw power from the 25 kV grid and quickly be able to supply this power to the electrical train system when a train starts. The energy storage device will be a megawatt scale magnetic flywheel, produced by the Danish company WattsUp Power. However,
current magnetic flywheel are not suited for use at railway transformer stations due to the large voltage and the vibrations from the trains. This will be mitigated by designing optimized power electronics and vibration-resistant magnetic bearings.
Once the optimized flywheel has been designed, it will be constructed and subsequently tested, first at DTU Elektro, and then at an electrical railway transformer station in Denmark, to demonstrate its real-world abilities to provide peak power shaving and energy storage. The flywheel technology can also
be used to shave peak fluctuation of energy sources, such as renewables. Thus, the demonstrated technology can potentially be used in the entire Danish electrical grid.
The concept of the project is illustrated in the figure below, which shows the traction load from the train and the shaved power profile, due to the energy provided by the flywheel.
